This invention relates to masonry structures in general, and more particularly to a technique for reinforcing existing masonry structures to provide greater structural strength and resistance to externally applied forces.
Known masonry structures typically comprise a series of rows of individual masonry elements, such as cement blocks, bricks and the like, adhered together using cementitious mortar or some other adhesive material. Both the mortar and the masonry elements exhibit inferior response to shear forces imposed on a masonry structure by external forces, such as winds and earthquakes, when compared to steel reinforced building structures. In addition, over time, the mortar deteriorates due to weathering, aging and other factors. As a result, the mortar loses adhesive strength, becomes soft and friable, thereby weakening the adhesive bond between the individual masonry elements. This further impairs the ability of such structures to withstand externally applied forces.
While efforts have been made in the past to reinforce existing mortar and masonry structures by using steel members, such as rods or beams, as part of a retrofitting operation, such efforts have been found to be either unreasonably expensive, incapable of retrofitting installation, incompatible with existing structures, relatively ineffective or a combination of these factors.
U.S. Pat. No. 4,694,621 for "Modular Building Constructing Means" issued Sep. 22, 1987, discloses a system for constructing modular metal buildings using a unique conical connector and fastening rods for connecting together the structural modules of a steel building. The unique conical connector is used in conjunction with a socket assembly rigidly secured to the building and a vertically oriented tensioning mechanism which passes through a bore in the connector in order to enable compressive/tensile force to be created in the vertical direction. A series of connectors, sockets and tensioning mechanisms are arranged in a vertical column from the foundation to the top of the building, and a plurality of such series of elements is provided in parallel columns distributed about and through the building. The system disclosed and claimed in the '621 patent, while effective, was designed expressly for use in steel building construction. The disclosure of U.S. Pat. No. 4,694,621 is hereby incorporated by reference.